The launch of Endeavour has been postponed for a fourth time and will hopefully take off later today. Image: NASA/Kim Shiflett.

The National Aeronautics and Space Administration (NASA) has once again postponed the launch of its space shuttle Endeavour after experiencing adverse weather conditions.

Endeavour was due to take off on Sunday (12 July) from NASA’s Kennedy Space Center in Florida but was halted only a few minutes before its liftoff. This is the fourth time the Endeavour has been postponed from launching.

The launch will now take place at 18:51 local time (22:51 GMT) today.

An earlier launch was also halted after NASA teams investigated lightening strikes near the launch pad.

Endeavour’s launch was originally planned for 13 June and was then rearranged for 17 June. Both launches were cancelled after leaks were discovered in the gaseous hydrogen venting system.

The 16-day mission will include five spacewalks lasting 32.5 hours and will complete the construction of the Japan Aerospace Exploration Agency’s Kibo laboratory. It will be the 32nd mission to the International Space Station (ISS), which orbits 350 kilometres above the Earth.

When the Endeavour finally takes off, it will be the 127th space shuttle flight, and the 29th mission to the ISS.

For more information about the Endeavour STS-127 mission, visit: http://www.nasa.gov/shuttle